Shouldn't line "481462609" contain only two nodes? Now it begins and ends in the same node, but tags don't indicate that this is polygon and polygon should contain at least 3 different nodes.

Niektóre linie (np. 670998635) nie mają żadnych tagów.

No - knowledge about tagging "pharmacy". If you check the history, you will notice that I changed tag shop=pharmacy to amenity=pharmacy